Abstract: In a cross section perpendicular to a rotational axis of a first image bearing member, when a common tangential line between the first image bearing member and a second image bearing member on an intermediary transfer belt side is a rectilinear line L, a rectilinear line passing through a rotation center of the first image bearing member and a rotation center of a first transfer member is a rectilinear line P, and a rectilinear line passing through an intersection point between the rectilinear line P and the first image bearing member and perpendicular to the rectilinear line P is a rectilinear line Q, an electrode member is constituted so that the contact portion contacting an inner surface of the belt is positioned on a first image bearing member side than the rectilinear line L is and on a first transfer member side than the rectilinear line Q is.

Abstract: An image forming apparatus includes an image forming portion, a belt, a plurality of stretching rollers including an inner roller and an upstream roller, an outer member, an urging member, a first position changing mechanism, a storing portion, a controller, and an operating portion. The controller controls the first position changing mechanism on the basis of a kind of a recording material on which an image is formed, first set information stored in the storing portion, and first input information for changing setting of a position of the urging member inputted to the controller through the operating portion.

Abstract: An image forming apparatus includes an image forming portion, a rotatable endless belt, a plurality of stretching rollers including an inner roller and an upstream roller, an outer member, a guiding member, a sheet-like pressing member, and a coating member. The coating member is disposed on the pressing member so as not to contact the belt and is electrically grounded or electrically conducted to the guiding member. The coating member is formed of a material lower in surface resistivity than the pressing member.

Abstract: An image forming apparatus includes an image forming portion, a transfer portion, a power source, a reading portion, and a controller. The controller executes an output operation so that first test images do not overlap with second test images, respectively, on a first side and a second side of a recording material. On the basis of information on a second test voltage for transfer of the second test image, of the plurality of second test images, of which information on a density read by the reading portion coincides with a preset condition, the controller sets a transfer voltage for image transfer onto the second side in double side image formation so that an absolute value of the transfer voltage set for the image transfer onto the second side in double side image formation is greater than an absolute value of the second test voltage that coincides with the preset condition.

Abstract: An image forming apparatus includes an image forming portion, a rotatable endless belt, a plurality of stretching rollers including an inner roller and an upstream roller, an outer member, a guiding member, a sheet-like pressing member, and a coating member. The coating member is disposed on the pressing member so as not to contact the belt and is electrically grounded or electrically conducted to the guiding member. The coating member is formed of a material lower in surface resistivity than the pressing member.

Abstract: An image forming apparatus includes an image forming portion, a belt, a plurality of stretching rollers including an inner roller and an upstream roller, an outer member, an urging member, a first position changing mechanism, a storing portion, a controller, and an operating portion. The controller controls the first position changing mechanism on the basis of a kind of a recording material on which an image is formed, first set information stored in the storing portion, and first input information for changing setting of a position of the urging member inputted to the controller through the operating portion.

Abstract: An image forming apparatus includes an image forming portion, a belt, a plurality of stretching rollers including an inner roller and an upstream roller, an outer member, an urging member, a first position changing mechanism, a storing portion, a controller, and an operating portion. The controller controls the first position changing mechanism on the basis of a kind of a recording material on which an image is formed, first set information stored in the storing portion, and first input information for changing setting of a position of the urging member inputted to the controller through the operating portion.

Abstract: An image forming apparatus includes an image forming portion, a transfer portion, a power source, a reading portion, and a controller. The controller executes an output operation so that first test images do not overlap with second test images, respectively, on a first side and a second side of a recording material. On the basis of information on the second test voltage for transfer of the second test image, of the plurality of second test images, of which information on a density read by the reading portion coincides with a preset condition, the controller sets a transfer voltage for image transfer onto the second side in double-side image formation so that an absolute value of the transfer voltage set for the image transfer onto the second side in the double-side image formation is larger than an absolute value of the second test voltage coincided with the preset condition.

Abstract: An image forming apparatus includes an image forming portion, a belt, an inner roller, an outer member, an inner roller position changing mechanism, an acquiring portion, and a controller. In a case that information acquired by the acquiring portion shows that first and second recording materials are coated paper, the controller controls a position changing mechanism so that a position of the inner roller when a toner image is transferred onto the second recording material is changed to a second position. In a case that the information acquired by the acquiring portion shows that the first and second recording materials are plain paper, the controller controls the position changing mechanism so that the position of the inner roller when the toner image is transferred onto the second recording material is maintained at a first position.

Abstract: An image forming apparatus includes an image forming portion, a belt, a plurality of stretching rollers including an inner roller and an upstream roller, an outer member, an urging member, a first position changing mechanism, a storing portion, a controller, and an operating portion. The controller controls the first position changing mechanism on the basis of a kind of a recording material on which an image is formed, first set information stored in the storing portion, and first input information for changing setting of a position of the urging member inputted to the controller through the operating portion.

Abstract: An image forming apparatus includes an image forming portion, a belt, an inner roller, an outer member, an inner roller position changing mechanism, an acquiring portion, and a controller. In a case that second information acquired by the acquiring portion shows that first and second recording materials are coated paper, the controller controls a position changing mechanism so that a position of the inner roller when a toner image is transferred onto the second recording material is changed to a second position. In a case that the second information acquired by the acquiring portion shows that the first and second recording materials are plain paper, the controller controls the position changing mechanism so that the position of the inner roller when the toner image is transferred onto the second recording material is maintained at a first position.